Most of the debate around renewable energy is focused on electricity generation. However in most industrialised countries electricity only accounts for about 25% of energy total energy use: transport accounts for another 25% and heating and cooling for a massive 50%. Reducing or eliminating the use of fossil fuels for heating and cooling is critically important as we seek to lower carbon emissions, cut air pollution and dependence on imported fuels. I’ve blogged about the excellent district heating systems in Denmark or in the Austrian village of Gussing, and last summer I blogged about Plas Newydd in Anglesey installing a marine source heat pump.
Adding large scale heat pumps into district heating systems, that might also utilize many other sources of heat, has great potential. Instead of thinking about individual houses having their own central heating systems we need to think about the best ways to heat whole towns.
Large scale heat pumps have a huge potential to take heat from rivers, the sea, sewers, data centres or other sources and concentrate this heat up to useful temperatures. The Glasgow based company Star Renewables manufactures some of the largest and most efficient heat pumps in the world. A couple of years ago they installed a 14 MW system in the Norwegian city of Drammen, which provides 85% of heating for the local district heating system, the other 15% being gas which is just used as additional heat in very cold weather. In Drammen the heat is extracted from the local fjord. Cranbrook is a new town being built in Devon that will utilize field scale solar hot water, which will heat water to 40 degrees Celsius, and then the heat pump will use cheap night time electricity to boost it to 80 degrees, suitable for the heating and hot water requirements of the rapidly growing new town of Cranbrook. This combination of technologies should mean that for every one unit of electricity used four units of heat will be produced, giving an unusually high efficiency to the system. It should also help balance electricity supply and demand on the grid by using electricity when it is cheap and delivering heat when it is needed, effectively creating a form of energy storage. Congratulations to Star Renewables: just the kind of technology we need more of!
Star Renewables http://neatpump.com/
Press coverage of Drammen project http://www.scottishenergynews.com/clyde-built-heat-pump-project-may-prove-20000-winner-for-glasgows-star-renewable-energy/ and Wikipedia https://en.wikipedia.org/wiki/Drammen_Heat_Pump